Hexosaminidase A and Total Hexosaminidase, Leukocytes
Use
Used for diagnosis and carrier testing of Tay‑Sachs disease (deficiency of Hexosaminidase A due to HEXA gene variants) and Sandhoff disease (deficiency of both Hexosaminidase A and B due to HEXB gene variants) in leukocytes. Differentiates between these lysosomal storage disorders via enzyme activity levels in white blood cells. Follow‑up molecular testing may be indicated for clarification of pseudodeficiency alleles or confirmation. Appropriate for males and pregnant or nonpregnant females.
Special Instructions
Not provided.
Limitations
Specimen cannot be frozen; gross hemolysis may lead to rejection. The assay may not detect rare variants or carrier states accurately without follow‑up molecular testing. Not FDA approved; performance characteristics established under CLIA. Pediatric reference ranges differ by age group.
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
Hexosaminidase Percent A
AnalyteHexosaminidase Total
Analyte
LOINC Codes
- 87544-3 - Hexosaminidase A & Total Pnl WBC-cCnt
- 24075-4 - B-NAH WBC-cCnt
- 23825-3 - Hexosaminidase A CFr WBC
- 59462-2 - Clinical biochemist review
- 18771-6 - Provider signing name
Result Turnaround Time
2-6 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
6 mL
Minimum Volume
5 mL
Container
ACD (yellow‑top) tube
Collection Instructions
Draw blood in ACD Solution A or B yellow‑top tube; send 6 mL refrigerated, with cold packs; keep cool, do not freeze; draw Monday through Thursday only and not the day before a holiday; package as close to shipping time as possible.
Storage Instructions
Refrigerated (preferred), ambient acceptable; do not freeze
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | Unacceptable |
Other tests from different labs that may be relevant